It has been known to use portable data storage modules, such as a vault cartridge, in such applications as credit cards and in controllers coupled to a host system.
One problem associated with the use of a conventional vault cartridge is that in order to couple data signals into and out of the cartridge it is often a requirement that the cartridge be accurately aligned with data coupling devices within a host system, the host system storing and retrieving the data within the vault cartridge. Another common requirement is that the vault cartridge be securely retained within the host to prevent its intentional or inadvertent removal from the host system. Such a removal during a time when the host is storing or retrieving data within the cartridge could result in the disruption and the loss of data stored within the cartridge. In those applications were the data represents, for example, valuable accounting data such as in a postage meter device, such a data loss may prove especially disadvantageous.
Another particular problem associated with the use of such modules is that in order to couple data signals into and out of the cartridge it is often a requirement that electrical terminals be exposed upon a surface of the cartridge. These terminals may take the form of a card edge connector type terminal or other types of exposed conductive surfaces which are operable for being mated with a suitable connector in a receptacle to which the cartridge is coupled. The terminals may also take the form of optical data transmission and reception devices. The exposure of the terminals may be disadvantageous for several reasons. For example, electrically conductive terminals may, under the influence of atmospheric moisture and contaminants, become oxidized thereby decreasing the conductivity of the terminals. Another disadvantage is that the terminals are exposed to sources of electrical discharge energy, such as static electricity. As is well known, static electricity may cause the degradation or the complete failure of integrated circuit devices which are subjected to a discharge of static electricity. Such integrated circuit devices may typically be included within the data storage module for the storage of data and for performing functions associated with the storage of the data. Optical-type terminals may also be susceptible to conducting static electrical discharges into the storage module. Also, the radiation transmission and reception means, such as a lens, must be maintained free of radiation absorbing contaminates such as dirt and grease.
Due to this requirement of previous data storage modules that the data coupling terminals be in physical contact or otherwise physically accessible to the host system mating terminals, the exposure of the terminals upon a surface of the data storage module can result in the overall degradation of the operation of the module or even in the complete failure of the module to reliably store data. This problem is especially acute in relatively small and portable data storage modules which by definition may be inserted and removed a number of times from a host system. Such modules may also be especially vulnerable in that they are typically carried about in a jacket or shirt pocket where the danger of exposure to static electric discharge is increased.
Another problem associated with some conventional vault cartridges relates to the providing of operating power to the cartridge. Some cartridges contain a central processing unit (CPU) which is operable for storing data within the memory and for performing other functions, such as accounting related functions. Many cartridges also contain a battery to provide operating power for the circuits contained therein. It has also been known to provide regulated DC power through electrical contacts exposed upon a surface of the cartridge.
As can be appreciated, there are a number of disadvantages inherent in the use of such power coupling techniques. For example, if a battery is to power all of the circuits within the cartridge for an extended period of time the storage capacity and, hence, the physical size of the battery may need to be excessively large.
For those cartridges that have terminals for the coupling of regulated DC power a plurality of such terminals may be required if the cartridge requires for operation several different DC voltages. Furthermore, inasmuch as the power terminals may be directly coupled to integrated circuits within the cartridge the terminals may conduct static electric discharges into the cartridge and directly into the circuits. As has been previously noted, such static electric discharges may degrade or cause the complete failure of the circuits. Also, during coupling of the cartridge to the power terminals the circuit ground or common connection may be made after the DC power connection, resulting in possible damage to the circuits.
It is therefore one object of the invention to provide a vault cartridge having data signal coupling and power coupling means which are not susceptible to coupling external electrical interference, such as static electricity, into the cartridge.
It is another object of the invention to provide a vault cartridge for storing valuable accounting data which is inherently rugged and immune to disruptive electrical interference.
It is a further object of the invention to provide a receptacle means for a vault cartridge which accurately aligns and retains the cartridge during the operation thereof and which furthermore comprises means for coupling data signals and operating power to the cartridge.
It is a still further object of the invention to provide a vault cartridge/vault receptacle system which comprises capacitive data signal coupling means and magnetic flux power coupling means.
It is one further object of the invention to provide a vault cartridge comprising conductive plate means disposed beneath an insulating surface thereof and a secondary of a power transformer having opposing ends exposed upon the surface, the conductive plate means being brought into registration with corresponding plate means by the action of a vault receptacle to form data signal coupling capacitors, the secondary of the power transformer also being brought into registration with a primary of a power transformer for coupling operating power into the cartridge.